M20 Turbo Oil Drain Location - Block or Oil Pan?

[McGyver]

I'm building an m20b27 turbo engine and intend to run an oil cooler and AC. All things equal, would it be better to tap the block for an oil drain or weld a bung to the oil pan?

I assume most people do the oil pan because its easy to take off and weld. The new engine is currently on a stand and still needs to be assembled. Is there any advantage to tapping the block while its easy to flush any debris out of it?

[reelizmpro]

Mine dumps back to the pan. Seems like the easiest way rather than messing with the iron block. Easier to replace the pan than the block as well if anything happens.

[McGyver]

Mine dumps back to the pan. Seems like the easiest way rather than messing with the iron block. Easier to replace the pan than the block as well if anything happens.

That's a good point about it being easier to replace the pan.

In this thread, varg mentioned the idea location would be in the block above the oil level, but most turbo m20s drain to the pain without an issue. I suppose I could angle the bung to adjust for the tilt of the engine.

https://www.r3vlimited.com/board/forum/e30-technical-forums/engine-drivetrain/forced-induction/9900864-m20-turbo-oil-drain-advice

[reelizmpro]

My oil drains back to the front of the pan, so there isn't any issues with the angle of the fitting.

[McGyver]

That makes a lot of sense, assuming there's room to route the drain and retain AC. Thanks!